Clinical characteristics of tinnitus annoyance and perception

Tinnitus, or the perception of sounds without an external source, affects up to 15% of the adult population worldwide. It relates to a number of psychological and psychiatric disorders such as psychological distress, insomnia and depression, and develops on a broad range of physical insults. To date, it is nearly impossible to obtain quantitative data on this symptom and thus complaints are often labelled as ‘only’ imaginary. Nevertheless, the sheer number of affected individuals makes it clear that tinnitus is everything but an orphan symptom. Variations in the clinical presentation may arise from the specific physical insult, the quality of first diagnosis and immediate medical aid as well as genetic predisposition. Thus, regional differences have to be considered when approaching tinnitus patients. The aim of this thesis was to study patient populations managed for tinnitus at the Department of Otorhinolaryngology - Head and Neck Surgery, Helsinki University Hospital (Helsinki, Finland). In the first study, we were able to show that music exposure even at low volume can pose a noise trauma and tinnitus occurs long before tone-audiometric hearing disabilities become evident. The alarming finding of the second study was its confirmation of pediatric tinnitus as a largely ignored symptom and that tinnitus in the childhood is under-diagnosed and this may have severe consequences for development of the individual. The third study could demonstrate that pupillometry can be considered as a viable option for studying autonomic activation in tinnitus subjects and emphasized the close link between tinnitus and depression. From our fourth study, a systematic literature review, we cannot clearly conclude if tinnitus and suicide are interrelated entities. The results of the last study indicate that tinnitus patients describe their own perceived tinnitus sound as well as external given sounds very divergent and therefore subjective tinnitus descriptions should be interpreted with great caution. Taken together, an early recognition of tinnitus symptoms may increase not only the overall quality of life of the affected patients, more importantly, it may decrease the risk of psychological and psychiatric co-morbidities and suicidal behavior. A major limitation still is that tinnitus lacks both, clear-cut biomarkers that are specific enough to be allocated solely to the symptom and methods that are sensitive enough to detect them.